standard has 7 distinct synonyms spread across 6 of its 11 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is nonstandard.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a basis for comparison; a reference point against which other things can be evaluated
“the schools comply with federal standards”
the ideal in terms of which something can be judged
“they live by the standards of their community”
a board measure = 1980 board feet
an upright pole or beam (especially one used as a support)
“distance was marked by standards every mile”
conforming to or constituting a standard of measurement or value; or of the usual or regularized or accepted kind
“windows of standard width”
established or well-known or widely recognized as a model of authority or excellence
“a standard reference work”
conforming to the established language usage of educated native speakers
“standard English”
1 of the 11 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for standard.
Synonyms, antonyms and the broader and narrower relations for standard come from Princeton University’s WordNet. Full sources and licences.